Blog

Your Source for Automatic Drills, Multiple Spindle Heads, and more

Standard NPT Tap Drill Sizes Chart

March 13th, 2013

posted by AutoDrill

StandardNPTTapDrillSizesChart.pdf

Standard NPT Tap Drill Sizes
NPT Size	Tap Drill Size (in.)	Decimal Equivalent (in.)
1/16 – 27	“C”	0.242
1/8 – 27	“Q”	0.332
1/4 – 18	7/16	0.438
3/8 – 18	9/16	0.562
1/2 – 14	45/64	0.703
3/4 – 14	29/32	0.906
1.0 – 11 – 1/2	1-9/64	1.141
1 – 1/4 – 11 – 1/2	1-31/64	1.484
1 – 1/2 – 11 – 1/2	1-23/32	1.719
2.0 – 11 – 1/2	2-3/16	2.188
2 – 1/2 – 8	2-39/64	2.609
3.0 – 8	3-15/64	3.234

1 Response to "Standard NPT Tap Drill Sizes Chart"

Machinist Family

July 9, 2014 at 10:35 pm

My spouse and I stumbled over here from a different page and thought I might check
things out. I like what I see so now i am following you.

Look forward to checking out your web page repeatedly.

©2021 AutoDrill. All Rights Reserved. Developed & Maintained by Daniel Anthony